# Create a transaction
# rollback transaction
# DDL statements are saved, DML statements are rolled back
# By default, Oracle is autocommit=OFF 

select * from x;

drop table x;

create table x
(
    PK   int,
    data varchar2(20)
);

insert into x values(1,'a');
insert into x values(2,'b');

update x set data='c' where PK=2;

select * from x;

rollback;

insert into x values(3,'A');

select * from x;